The present invention relates generally to a window assembly and, more particularly, to a movable vehicle window assembly including a transparent sheet functioning as a retention shield and an edge support attached along at least a portion of the periphery of the sheet.
Initially, fixed window assemblies for vehicles were comprised of a plurality of elements including adhesive sealants applied around the marginal edges of the glass sheet, suitable mechanical fasteners such as metal clips, and exterior decorative trim strips disposed to cover the junction between the marginal edges of the glass sheet and the adjacent portions of the vehicle frame. Such window structures were costly, especially from a labor standpoint, since it was necessary to assemble the individual elements along the vehicle assembly line.
Subsequently, in an endeavor to improve the above window structure, unitary window assemblies of the type illustrated in U.S. Pat. No. 4,072,340 were developed. These assemblies included a sheet of glass, an adjacent frame, and a casing or gasket of molded material, such as polyvinylchloride, extending between the frame and the peripheral edge of the window to hold the sheet of glass and the frame together. Fasteners were provided at spaced locations along the frame such that the entire assembly could be guided into location over the opening in a vehicle body as a unit. Other types of unitary window assemblies are disclosed in U.S. Pat. Nos. 3,759,004 and 4,364,595. While such unitary window structures greatly reduce the time required to mount the window assembly in the associated vehicle, such structures are relatively costly, since the individual components required to produce each window assembly generally must be manually assembled.
Moveable vehicle windows also presented problems, especially as the window glass became curved. Seals were typically attached to the door frames on either side of the channel in which the window traveled. In a hard top or convertible, a seal was typically attached to the leading edge of the rear window to engage the trailing edge of the door glass. Such window structures were costly to assemble and made it difficult to eliminate wind noise and leaking.
In the early stages of the automobile industry, single sheets of ordinary glass were employed as windshields. As it became evident that this type of windshield presented a considerable safety hazard, the single sheets of ordinary glass were replaced with single sheets of heat treated or tempered glass. Thereafter, as laminated safety glass was developed to reduce the severity of lacerative injuries, its use in automotive windshields greatly increased until today, when almost all automotive windshields are constructed of some type of laminated glass.
Typically, laminated glass of the type utilized in vehicle windshields consists of two sheets of glass bonded together with a thin plastic interlayer, such as a sheet of polyvinyl butyral, for example. In the event of an impact on a laminated glass windshield sufficient to break the glass, the plastic interlayer functions to bind the glass fragments together, thus reducing the risk of injury to a driver or passenger as a result of flying glass or contact with the windshield. Further developments with this type of laminated glass, such as those disclosed in U.S. Pat. No. 3,231,461, have resulted in laminated windshields with improved penetration resistance. Consequently, with the ever growing recognition of the necessity for increased safety precautions, continuing efforts have been and are still being made to appreciably reduce the injury producing potential of automobile windshields.
Recently, it has been found that an addition of a second plastic layer bonded to the inner glass surface of the laminated windshield further increases the safety effectiveness of the windshield. This second plastic layer has typically been termed a protective laceration inhibiting shield since it has been found that the additional plastic layer will appreciably reduce the number and severity of lacerative injuries to persons thrown against the windshield under all impact conditions. Further, it has been found that the laceration shield when produced under certain conditions of manufacture improves the ability of the laminated windshield to decelerate movement of the person thrown against the windshield, while also increasing the penetration resistance of the windshield as compared to conventional laminated windshields. Also, the laceration shield reduces the amount of flying glass and thus the injury to car occupants as a result of objects that may be thrown against the windshield from overpasses or elsewhere outside the vehicle.
An example of an automotive windshield which incorporates, as part of its laminated structure, a protective laceration shield bonded to its inboard glass surface is disclosed in U.S. Pat. No. 4,242,403. In this patent, the laceration shield includes a penetration resisting multi-layer body consisting of an inner layer of relatively soft, extensible plastic material such as polyvinyl butyral, for example, which is adhered to the inboard surface of the windshield, an intermediate layer of more durable plastic such as polyester, and an outer coating of an abrasion resistant material.
While anti-lacerative or retention shield window assemblies are commonly utilized in vehicle windshields, the side windows of a vehicle present a unique problem. Most side windows are required to be movable so that they can be raised and lowered in the window frame opening in a vehicle door or vehicle body. In order to seal between the window opening and the window assembly, one or more of various types of sealing means are utilized such as rubber or plastic gaskets. These gaskets would tend to mar and scratch the relatively soft retention shield material if such material were adhered to the inner surface of a moveable side window.
U.S. Pat. No. 4,490,942 discloses a vertically adjustable window panel which is arranged so as to be flush with the adjacent parts of the vehicle body and in which guide means and window sealing means therefor are disposed inboard of the window panel. A profiled sealing strip of rubber or plastic material extends about the frame on the top and opposed sides. A guide rail is attached to each of the vertical side edges of the window panel. The guide rail includes a guide arm which extends interiorally of the window panel and longitudinally of the window panel and is received within a recess formed by the window frame and the sealing means.
U.S. Pat. No. 4,494,337 discloses a motor vehicle side window assembly in which the door glass weather strip is provided on the door frame in such a manner that it contacts the interior surface of the door glass. A slide piece is attached to the edge of the door glass and engages a guide in the door frame to guide the door glass in a vertical direction. The outer surface of the door glass is substantially flush with the outer surface of the door frame.
U.S. Pat. No. 4,502,248 discloses a vehicle window assembly including a slidable window glass supported by and guided along only one edge of the glass. A pillar is secured to the vehicle door at one side of a window opening and forms a channel for slidably retaining a guide bonded to one edge of the window glass.
U.S. Pat. No. 4,561,211 discloses a pair of U-shaped guides formed on either side of a window frame in a vehicle door. A window pane has a pair of guides formed of plastic material and adhesively bonded to its inner surface. The guides each have a slot formed therein for engaging a portion of the U-shaped guides on the window frame to aid in the raising and lowering of the window assembly.
All of these window assemblies are relatively costly since the individual components required to produce each window assembly are numerous and generally must be manually assembled.